From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9850CCA0EC4 for ; Mon, 11 Aug 2025 22:02:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:To:Subject :MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RuetYjBjH9nVj0M5j0Mkl5rej27wV4Ju+ZdjphNu78w=; b=H0CvrwTo/wLd4Z TTgVQISOBBNvjRFiA8r0IYeggl5yn0VBH8GgF+6mPrEZ4rcdmjO1jUYh6PuHqRMTjqgo/ypUNs1aS Ed8ZB/FNDLIeJLLjmGzW8IZGdGjSKxsC/Zf6PGPcULel3eL9YXBO73E4YLQ4h3UMytj3UUhzDOorM XbCAbQW5JjIJk5HwZLjOLOhMcVss/zDjTDzKkQ3/llToOlTFzZkKPVyKeMiaOmDdS6d02O6wZMgjM iehUWOC6R2cKm75odPiQTvvcffwSgY1o27vOjrlGFHBY+VSPcxsPi5zFQzUa0DneDUY87S5cnoJk4 HDon+2wilirnEyQfu1lA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ulaai-000000099R5-49j6; Mon, 11 Aug 2025 22:02:04 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ulUz3-00000008JvT-2sBR for linux-arm-kernel@lists.infradead.org; Mon, 11 Aug 2025 16:02:50 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CC053266C; Mon, 11 Aug 2025 09:02:40 -0700 (PDT) Received: from [10.1.28.163] (e137867.arm.com [10.1.28.163]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BCB213F738; Mon, 11 Aug 2025 09:02:44 -0700 (PDT) Message-ID: <4242ef37-efeb-446f-abbc-0104b805ad12@arm.com> Date: Mon, 11 Aug 2025 17:02:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH -next v7 5/7] arm64: entry: Refactor preempt_schedule_irq() check code To: Jinjie Ruan References: <20250729015456.3411143-1-ruanjinjie@huawei.com> <20250729015456.3411143-6-ruanjinjie@huawei.com> From: Ada Couprie Diaz Content-Language: en-US Organization: Arm Ltd. In-Reply-To: <20250729015456.3411143-6-ruanjinjie@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250811_090249_799117_18D99452 X-CRM114-Status: GOOD ( 15.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, sstabellini@kernel.org, puranjay@kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, liaochang1@huawei.com, oleg@redhat.com, kristina.martsenko@arm.com, linux-kernel@vger.kernel.org, broonie@kernel.org, chenl311@chinatelecom.cn, xen-devel@lists.xenproject.org, leitao@debian.org, ryan.roberts@arm.com, akpm@linux-foundation.org, mbenes@suse.cz, will@kernel.org, ardb@kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 29/07/2025 02:54, Jinjie Ruan wrote: > ARM64 requires an additional check whether to reschedule on return > from interrupt. So add arch_irqentry_exit_need_resched() as the default > NOP implementation and hook it up into the need_resched() condition in > raw_irqentry_exit_cond_resched(). This allows ARM64 to implement > the architecture specific version for switching over to > the generic entry code. > > To align the structure of the code with irqentry_exit_cond_resched() > from the generic entry code, hoist the need_irq_preemption() > and IS_ENABLED() check earlier. And different preemption check functions > are defined based on whether dynamic preemption is enabled. > > Suggested-by: Mark Rutland > Suggested-by: Kevin Brodsky > Suggested-by: Thomas Gleixner > Signed-off-by: Jinjie Ruan > --- Unrelated to the other thread : I noticed that compiling this patch with `allnoconfig` would fail : - `raw_irqentry_exit_cond_resched` has no previous prototype,   as it is defined within `#ifdef CONFIG_PREEMPTION` - `irqentry_exit_cond_resched()` is not declared, as it is also within   `#ifdef CONFIG_PREEMPTION` The patch below fixes the issue, but introduces merge conflicts in patches 6 and 7, plus the `#ifdef` needs to be moved accordingly in patch 6 and the empty "without preemption" `irq_exit_cond_resched()` needs to be removed in patch 7. I hope this can be useful, Ada --- diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h index 0f0ba250efe8..d9aba8b1e466 100644 --- a/arch/arm64/include/asm/preempt.h +++ b/arch/arm64/include/asm/preempt.h @@ -103,6 +103,8 @@ void dynamic_irqentry_exit_cond_resched(void);  #define irqentry_exit_cond_resched() raw_irqentry_exit_cond_resched()  #endif /* CONFIG_PREEMPT_DYNAMIC */ +#else /* CONFIG_PREEMPTION */ +#define irqentry_exit_cond_resched() {}  #endif /* CONFIG_PREEMPTION */  #endif /* __ASM_PREEMPT_H */ diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 4f92664fd46c..abd7a315145e 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -661,6 +661,7 @@ static __always_inline void __el1_pnmi(struct pt_regs *regs,         arm64_exit_nmi(regs, state);  } +#ifdef CONFIG_PREEMPTION  void raw_irqentry_exit_cond_resched(void)  {         if (!preempt_count()) { @@ -668,6 +669,7 @@ void raw_irqentry_exit_cond_resched(void)                         preempt_schedule_irq();         }  } +#endif  #ifdef CONFIG_PREEMPT_DYNAMIC  DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);